Net Speedometer

Net Speedometer is a lightweight Windows tool that can show network statistics in a plain and simple interface.
You don't have to be a professional user to look for such an application and given the limited number of features Net Speedometer provides, this is clearly a handy app aimed at rookies.
The plain and simple GUI we were talking about is actually the statistics screen that shows you current, average and maximum download and upload rates.
Nothing more, just the aforementioned figures in a very clean design. Right-clicking this main window however lets you reset the stats, but also enter options to configure the app.
You can for instance change text font and colors, background colors and the network card to be tracked, especially useful in case multiple adapters are installed on your system. Unfortunately, you cannot monitor more than a single connection at the same time.
As you can see, Net Speedometer is a very easy to use piece of software, so it's no surprise that it works flawlessly on all Windows iterations on the market. A help manual is not available, but chances are that you don't even need one since everything's so basic and intuitive.
To sum up, Net Speedometer may come in handy, but only to those uninitiated who aren't willing to spend too much time setting up complex software solutions. The basic interface and the reduced number of features should do the job, unless you're looking for many more customization options.